1. LESSON LESSON INTRODUCTION Get Ready Before you begin, decide if you agree or disagree with each of these statements. As you view this presentation, see if you change your mind about any of the statements. 4 Chemical Properties and Changes What do you think?

2. Get Ready LESSON LESSON INTRODUCTION Do you agree or disagree? When wood burns, new materials form. Temperature can affect the rate at which chemical changes occur. 4 Chemical Properties and Changes

3. Key Concepts/Essential Questions LESSON LESSON INTRODUCTION 4 Chemical Properties and Changes What is a chemical property? What are some signs of chemical change? Why are chemical equations useful? What are some factors that affect the rate of chemical reactions?

4. Vocabulary Watch out for these words! LESSON LESSON INTRODUCTION chemical property chemical change concentration 4 Chemical Properties and Changes

5. LESSON LESSON INTRODUCTION 4 Chemical Properties and Changes A Burning Issue? Look at the photo at the beginning of the lesson. As this car burns, some materials change to ashes and gases. The metal might change form or state if the fire is hot enough, but it probably won’t burn. Why do fabric, leather, and paint burn? Why do many metals not burn? The properties of matter determine how matter behaves when it undergoes a change.

6. Chemical Properties and Chemical Changes Ch-7, Lesson 4

7. Chemical Change The identity of the material changes. produces a new material with a new set of properties. Chemical Properties, like flammable and corrosive, tell us whether a material can go through a chemical change.

8. Signs of Chemical Change 1. formation of bubbles without boiling – Chalk and acid, baking soda and vinegar 2. change in color (not caused by mixing) – Leaves changing colors 3. change in energy involving giving off light or temperature changes – Fireworks, Glow stick 4. change in odor – Rotting fruit/eggs 5. precipitate forms – Insoluble solid forms in a solution

9. The Rate of Chemical Changes Chemical reactions will happen more quickly if the particles move faster and collide more often. To Speed Up a Chemical Change: – 1. Increase the temperature of the reactants. – 2. Increase the concentration of the reactants. (Have more reactants available to react.) – 3. Increase the surface area of the reactants.

10. Chemical Reactions During chemical reactions, the bonds between atoms break apart. The atoms then rearrange and form new bonds.

11. Chemical Equations Reactants Products 2 H 2 + O 2  2 H 2 O Coefficient Plus Yields

12. Chemical Equations are Useful Because… 1. They tell us the chemical formulas of substances involved in the change. 2. They tell us the reactants required. 3. They tell us the new products produced. 4. They tell us how much of the reactant is needed and how much product is produced.

13. Does this chemical change follow the Law of Conservation of Mass? 2 H 2 + O 2  2 H 2 O

14. CH 4 + O 2  CO 2 + H 2 O Label the parts and determine if it is balanced.

15. 2 Fe + 3 O 2  2 Fe 2 O 3

16. Lesson Review LESSON LESSON WRAP-UP When wood burns, new materials form. Do you agree or disagree? 4 Chemical Properties and Changes Agree. When wood burns, new materials form, such as water and carbon dioxide.

17. Lesson Review LESSON LESSON WRAP-UP Temperature can affect the rate at which chemical changes occur. Do you agree or disagree? 4 Chemical Properties and Changes Agree. In general, increased temperature increases the rate of chemical change.

18. Key Concept/Essential Question Review LESSON LESSON WRAP-UP What is a chemical property? 4 Chemical Properties and Changes Chemical properties include ability to burn, acidity and ability to rust.

19. Key Concept/Essential Question Review LESSON LESSON WRAP-UP What are some signs of chemical change? 4 Chemical Properties and Changes Some signs that might indicate chemical changes are the formation of bubbles and a change in odor, color, or energy.

20. Key Concept/Essential Question Review LESSON LESSON WRAP-UP Why are chemical equations useful? 4 Chemical Properties and Changes Chemical equations are useful because they show what happens during a chemical reaction.

21. Key Concept/Essential Question Review LESSON LESSON WRAP-UP What are some factors that affect the rate of chemical reactions? 4 Chemical Properties and Changes Some factors that affect the rate of chemical reactions are temperature, concentration, and surface area.